146 TRICHOPTERYGIDA. 
than Nanosella fungi, the smallest coleopteron yet discovered. ‘The following super- 
ficial characters will serve to distinguish them from each other :— 
Form oblong. . . . 1. . 1 ee ee ee ee) ornianum. 
Form elongate. 
Antenne moderate . . . . . . . + + + ~) 6planum. 
Antenne very short and robust . . . . . + . ¢ropicum. 
1. Ptilium hornianum. 
Ptilium hornianum, Matth. Trans. Am. Ent. Soc. xi. p. 143°. 
Oblongum, convexum, sat nitidum, castaneum, pilis griseis vestitum ; capite magno, lato; oculis modicis, promi- 
nulis; pronoto parvo, transverso, quam caput breviore vix latiore, nitido, tuberculis exiguis confertim 
obtecto, ad medium latissimo, lateribus leviter rotundatis, leviter marginatis, margine basali leviter reflexa, 
angulis fere rectis; elytra oblongis, quam caput atque pronotum parum longioribus, vix latioribus, profunde 
et reticulatim asperatis, ad media latissimis, lateribus minime rotundatis, apice lato rotundato; pedibus 
lete, antennis obscure flavis. Long. corp. 7% lin. =0-37 millim. 
Head large and broad, rather prominent, shining, closely but finely tuberculate ; eyes moderate, rather promi- 
nent ; antenne rather long, dusky yellow. Thorax small, transverse, shorter and scarcely broader than 
the head, rather shining, closely but finely tuberculate, widest at the middle; sides a little rounded and 
faintly margined ; basal margin straight, slightly reflexed, with the angles almost rectangular. Scu- 
éellum small, triangular, closely asperate. Hlytra oblong, convex, rather longer but scarcely wider than the 
head and thorax, widest at the middle, deeply and reticulately asperate; sides slightly rounded ; apex 
broad and much rounded. Abdomen with the pygidium only exposed and pale. Legs moderate, bright 
yellow. Underparts pale castaneous, with the mouth, the hinder part of the metasternum, and the 
terminal segments of the venter flavescent. 
Hab. Nortu America, Texas !.—GuateMa.a, El Reposo 800 feet (Champion). 
Differs from the European P. rugulosum in its much smaller size, fainter sculpture, 
shining surface, and bright yellow legs and antenne; from all others of the genus in 
its exceedingly minute size. 
2. Ptilium planum. 
Ptilium planum, Matth. Trans. Am. Ent. Soc. xi. p. 144". 
Elongatum, fere lineare, modice convexum, haud nitidum, ferrugineum, pilis flavis dense vestitum ; capite magno, 
antice producto; oculis magnis, valde prominentibus ; pronoto parvo, transverso, quam caput breviore haud 
latiore, confertim tuberculato, lateribus ante media latioribus ad basin fortiter contractis; elytris longis, 
angustis, quam caput atque pronotum plus quam sesqui-longioribus, vix latioribus, leviter sed confertim 
asperatis, apicibus latis rotundatis ; pedibus longis, gracilibus, flavis; antennis sat brevibus, lete flavis. 
Long. corp. 39; lin. =0°63 millim. 
Head very large, produced in front, dusky ferruginous, closely and finely tuberculate; eyes large and promi- 
nent; antenne rather short, bright yellow. Z'horawx small, transverse, narrower and not longer than the 
head, closely and finely tuberculate ; sides much contracted towards the base, widest before the middle, 
and moderately margined; the basal margin nearly straight, with the angles almost rectangular. 
Scutellum large, triangular, closely asperate. Hlytra elongate oval, scarcely wider but more than half as 
long again as the head and thorax, finely and closely asperate in transverse rows, with the apex broad 
and rounded. Abdomen with the pygidium only exposed. Legs long and slender, yellow. Underparts 
wholly testaceous. 
Hab. GuatEmata, Capetillo (Champion *). 
